A Shot in the Arm

Why do people ignore the science behind vaccines and the subjects of other false controversies?

I got a DPT booster the other day when I visited Silver Health Care for a checkup. Of the three diseases making up that acronym — diphtheria, pertussis and tetanus — I was most concerned about pertussis, also known as whooping cough. I'd had the DPT vaccine as a kid, and until recently would have sought out a booster only if I'd stepped on a rusty nail or something else classically associated with tetanus. But New Mexico had 527 reported cases of pertussis in 2013 — fourth in the nation when figured per capita.

I also vividly remembered reading an article in The New Republic online in which the 31-year-old author, Julia Ioffe, wrote of coughing constantly for 72 days — "not just coughing, but whooping: doubled over, body clenched, sucking violently for air, my face reddening and my eyes watering." This was written in 2013, not 1913 or some other year before the 1940 discovery of a vaccine against whooping cough. (Before that vaccine, 200,000 children were infected annually.) And yet from 2011 and 2012, reported cases of pertussis — a preventable disease — tripled in 21 states and totaled a record 38,000-plus nationwide.

Pertussis isn't the only once-vanquished disease making a comeback. The Centers for Disease Control and Prevention (CDC) tracked 554 cases of measles in 20 states (including Texas but not New Mexico) in the first half of this year alone. That's already a record, and the highest number of cases since measles was deemed eliminated in the US — again, thanks to vaccination — in 2000.

Many doctors today are too young to even remember measles, but I vividly recall how it swept through my elementary school. I was lucky, suffering no more than the usual fever and rash. Before the measles vaccine, however, up to 4 million Americans a year were infected; 1,000 suffered brain damage or hearing loss annually and 450 died.

A 2013 University of Pittsburgh study calculated that vaccination programs for children have prevented more than 100 million cases of serious contagious diseases since 1924. In 2007, death rates for 13 diseases preventable by childhood vaccines reached an all-time low in the United States.

What in the world could have caused these nearly vanished diseases to return? Absent an encounter with a rusty nail, why would I need a DPT booster at my age?

In the headline of her much-linked-to New Republic account, Ioffe provides an answer, albeit a tad hyperbolic (forgivable if you've been coughing for 72 straight days): "I've Got Whooping Cough. Thanks a Lot, Jenny McCarthy!" McCarthy, a former Playboy model and briefly cohost of "The View," has been blamed by many for spreading fears about dangers from vaccines. There's even a "Jenny McCarthy Body Count" page on the web that tallies tthe number of preventable illnesses (137.900 as of early
August) and deaths (6,265) since McCarthy and other celebrities ramped up anti-vaccination rhetoric in mid-2007. The page also counts the "number of autism diagnoses scientifically linked to vaccinations" in that span — zero.

Autism fears are only part of the anti-vaccination hysteria, but they have fueled other, equally unsubstantiated concerns. The supposed link between the measles, mumps and rubella (MMR) vaccine and autism originated in a study published in 1998 by Dr. Andrew Wakefield, involving only 12 patients. A subsequent investigation showed that the British gastroenterologist misrepresented and altered his findings in an "elaborate fraud"; 10 of 12 authors of the paper have retracted it. A second Wakefield study in 2002 also contained what the American Academy of Pediatrics calls "critical flaws."

Other anti-vaccination fearmongers have blamed the mercury compound thimerosal, used as a preservative in some vaccines (though not the MMR shot), for the rise in autism. Yet autism diagnoses have not declined since 1999, when thimerosal was discontinued in all the most common vaccines.

The purported link between vaccines of any kind and autism risk has been thoroughly debunked. In 2013, a study of more than 1,000 children published in the Journal of Pediatrics found no association between autism and either the number of vaccinations a child was given or the total number of antigens.

If you're nonetheless worried about this nonexistent risk, or simply fear that your kids are getting "too many" shots, why should that matter to anybody else? As Ioffe explained, in-between hacking coughs: "The problem is that it is not an individual choice; it is a choice that acutely affects the rest of us. Vaccinations work by creating something called herd immunity: When most of a population is immunized against a disease, it protects even those in it who are not vaccinated, either because they are pregnant or babies or old or sick."

To protect those who can't be vaccinated, herd immunity requires immunization of about 95% of the total population. But anti-vaccination fears have reduced immunization below that critical threshold in some places. In 2010, for example, only 91% of kindergarteners were up to date on their shots in California — which saw a major pertussis outbreak.

No vaccine — or any medical treatment — is completely safe. But the ratio of serious adverse reactions to beneficial effects for the most common vaccines is about 1 to 40,000. By focusing on anecdotal evidence of purported harm instead of the overwhelming societal benefits of immunization, ill-informed celebrities and others seeking to fix blame for their personal tragedies have created a debate where in reality the facts are not in dispute. The result has been to turn back the clock on one of the great accomplishments of public health.

By giving people like Jenny McCarthy a forum, the media is in part to blame. Interestingly, this summer the BBC Trust published an update on a year-old policy questioning the "over-rigid application of editorial guidelines on impartiality" in science reporting. BBC journalists, it said, are often guilty of "false impartiality" — that is, "presenting the views of tiny and unqualified minorities as if they have the same weight as the scientific consensus."

Imagine, for example, if every time the news reported something about global travel or orbiting satellites, a flat-earth fanatic also got air time for an "opposing view." No broadcast about firefighting would be complete without counterpoint from a spokesperson for phlogiston, the medium thought to make combustion possible until science proved otherwise.

But that's essentially what the media are doing with some contemporary controversies where there is in fact overwhelming scientific consensus. The BBC report cited as examples global warming, worries over the safety of GMO foods — and vaccines. Evolution by natural selection is another obvious example. You may choose to believe vaccines cause autism or the earth is not getting warmer (as 26% in a recent Pew poll stated) or "humans and other living things have existed in their present form since the beginning of time" (a view held by 33% in that same poll). But there is no serious scientific debate about these questions. (Not only is the earth getting warmer, for example, but 97% of climate scientists believe humans are contributing to it.)

If only, you might think, we could explain the facts to the public! Unfortunately, a new study by Yale law professor Dan Kahan finds, as the New York Times reported, "more people know what scientists think about high-profile scientific controversies than polls suggest; they just aren't willing to endorse the consensus when it contradicts their political or religious views." Kahan didn't find a gap in knowledge on matters such as evolution: "Religious people knew the science; they just weren't willing to say that they believed in it."

Once political or religious/spiritual identities get entangled with scientific issues, Kahan says, it's difficult for contrary facts to penetrate. "Cosmos" host Neil deGrasse Tyson can lecture endlessly about global warming or evolution, but the skeptics won't hear him. A more effective voice on global warming, for example, might be Katherine Hayhoe, a climate scientist who is also an evangelical Christian. News media in search of "balance" might consider airing such views that support the science but from a different perspective.

On vaccines, it's helpful that TV's "Dr. Oz," who has given credence and air time to a distressing array of quackery, recently wrote about the importance of childhood immunization. Parents might also need to hear from celebrities besides Jenny McCarthy. Sarah Michelle Gellar ("Buffy the Vampire Slayer"), for example, recently told Parade Magazine why she supports vaccination: "Having children is the greatest gift anyone's ever given me, and if I can help protect anyone else's gift, then it's not just my pleasure, but it's my responsibility to do it." Jennifer Lopez, mother of twins, is an advocate for the pertussis vaccine and a spokesperson for the Silence the Sounds of Pertussis campaign.